Stop Being Bombarded by 'UserImages.bmp'

I keep finding a file called UserImages.bmp in random folder accross my 2 HDD's. Where is it coming from and how am I going to stop it (I am already running Zone Alarm 6 Pro, Spybot S&D, Windows Defender)

It is a 672x16 image showing smiley faces and other small icons/cursors in the one image.